Field
The disclosure relates to a mobile communication device and a radiated power adjusting method thereof, and more particularly, to a mobile communication device that adjusts a radiated power according to a parameter of a signal sensed by an antenna, and a method of adjusting the radiated power of the mobile communication device.
Description of Related Art
As wireless communication technology advances and develops, mobile communication devices have been widely used in our daily life. All mobile communication devices are equipped with an antenna for transmitting and receiving wireless signals, but electromagnetic waves radiated from the antenna may be harmful to human health. Therefore, the Federal Communications Commission (FCC) in the United States has specified a specific absorption ratio (SAR) for mobile communication devices so as to set an upper limit on the amount of energy or radiation that is allowed to be emitted from the mobile communication devices, thereby protecting human bodies from the danger of the electromagnetic waves radiated from the antenna.
The SAR refers to energy of the electromagnetic waves absorbed per unit mass per unit time. Thus, the higher the SAR, the more damage may be done to the human bodies. To satisfy the SAR value regulated by the FCC, the mobile communication devices nowadays are mostly provided with a proximity sensor at a side of the antenna. The proximity sensor includes a sensing capacitor and a sensing controller. Accordingly, when a human body approaches the antenna, variation occurs in charges of the sensing capacitor in response to the approach. In addition, the sensing controller notifies a system to reduce a radiated power of the antenna, thus preventing excessive absorption of the energy by the human body.
However, the proximity sensor often makes an erroneous determination due to environmental factors, or even cannot return to an original state in which no object is detected. If the proximity sensor fails to operate correctly, the mobile communication device is not able to properly adjust the radiated power of the antenna. Once the radiated power of the antenna cannot be properly adjusted, the reduction of the SAR cannot be duly performed. As a result, the radiated power of the antenna fails to comply with the SAR value set by the FCC.